I wouldn't be surprised if he stirred it with his finger.
He poured the cold water over the ration and stirred it with his finger.
The reporter poured himself a healthy drink, stirred it with his finger, then took a deep swallow.
"Which you fully intend to stir with your finger ?"
You can stir boiling water with your finger if you don't leave it in too long.
She stirred the ten coins with her finger.
She stirred it with her finger until it was a watery white fluid.
She scooted closer to Jack, stirred the ice in his drink with her finger, and then licked it off.
Reaching into the heat, she stirred it with her finger.
While he waited he tried to stir the substance with his middle finger.